Method for cutting liquid crystal display panel and method for fabricating liquid crystal display panel using the same

ABSTRACT

A method for cutting a liquid crystal display panel including: forming prearranged cut lines on a pair of attached mother substrates on which a plurality of panel regions have been disposed; and separating the liquid crystal display panel from a dummy glass around the liquid crystal display panel through a transfer unit which includes a body for adsorbing a liquid crystal display panel and transferring it, and a plate attached on an edge of the body, fixing and separating a dummy glass of a mother substrate from the liquid crystal display panel, and moving up and down separately from the body. A dummy removing plate is attached at an edge of a trans hand to remove a dummy glass when a breaking process-finished liquid crystal display panel is extracted, so a damage of the liquid crystal display panel due to the dummy glass can be prevented.

This application is a Divisional of application Ser. No. 11/477,789,filed Jun. 30, 2006, now U.S. Pat. No. 7,495,741 now allowed; whichclaims priority to Korean Patent Application No. 10-2005-0134396, filedDec. 29, 2005 all of which are hereby incorporated by reference as iffully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for cutting a liquid crystaldisplay panel and, more particularly, to a method for cutting a liquidcrystal panel to cut a plurality of liquid crystal display panel formedon large-scale mother substrates into a plurality of unit liquid crystaldisplay panels, and a method for fabricating a liquid crystal displaypanel using the same.

2. Description of the Related Art

As the consumers' interest in information displays grows and the demandfor portable (mobile) information devices increases, research andcommercialization of light and thin flat panel displays (“FPD”) hasincreased. Flat panel displays may replace the Cathode Ray Tube (“CRT”),which is the most common existing display device.

The liquid crystal display (“LCD”) device is a FPD device for displayingimages using optical anisotropy of liquid crystal. LCD devices exhibitexcellent resolution and color and picture quality, so it is widelyapplied for notebook computers or desktop monitors, and the like.

The LCD device will now be described in detail.

The general LCD device includes a liquid crystal display panel includinga driving circuit unit, a backlight unit installed at a lower portion ofthe liquid crystal display panel and emitting light to the liquidcrystal display panel, a mold frame for supporting the backlight unitand the liquid crystal display panel, and a case, etc.

With reference to FIG. 1, the liquid crystal display panel 10 includesan image display part 13 in which liquid crystal cells are arranged in amatrix form, a gate pad part 14 connected with gate lines 16 of theimage display part 13 and a data pad part 15 connected with data lines17.

The gate pad part 14 and the data pad part 15 are formed at an edgeregion of a thin film transistor (TFT) array substrate which does notoverlap with a color filter substrate 2. The gate pad part 14 suppliesscan signals provided from a gate driver (not shown) to the gate lines16 of the image display part 13, and the data pad part 15 supplies imageinformation provided from a data driver (not shown) to the data lines 17of the image display part 13.

Although not shown, the color filter substrate 2 includes a color filterincluding red, green and blue sub-color filters implementing colors, ablack matrix for separating the sub-color filters and blocking lightfrom transmitting through a liquid crystal layer, and a transparentcommon electrode for applying a voltage to the liquid crystal layer.

The array substrate 1 includes a plurality of gate lines 16 and aplurality of data lines 17 arranged vertically and horizontally thereonand defining a plurality of pixel regions, the TFT, namely, a switchingelement, formed at each crossing of the gate lines 16 and the data lines17, and a pixel electrode formed on each pixel region.

The array substrate 1 and the color filter substrate 2 are attached in afacing manner by a seal pattern 40 formed at an edge of the imagedisplay part 13 to form a liquid crystal display panel 10, andattachment of the two substrates 1 and 2 is made through an attachmentkey (not shown) formed on the array substrate 1 or the color filtersubstrate 2.

In order to seek improvement of a yield, in the LCD device, the TFTarray substrates are formed on a large-scale mother substrate, colorfilter substrates are formed on another separate mother substrate, whichare then attached to simultaneously form the plurality of liquid crystaldisplay panels. In this case, for the attached mother substrates, acutting process is required to cut the attached mother substrates into aplurality of unit liquid crystal display panels.

In general, cutting of the mother substrates is performed such that aprearranged cut groove is formed on the mother substrates with a wheelwith high hardness compared with glass and then cracking is made alongthe prearranged cutting groove.

FIG. 2 is a view showing the structure of a section of the unit liquidcrystal display panel formed by attaching the first mother substrate onwhich the TFT array substrates are formed and the second mothersubstrate on which the color filter substrates are formed.

As shown, in the unit liquid crystal panels, the thin film transistorarray substrates 1 are protruded at one side compared to the colorfilter substrates 2, because the gate pad part (not shown) and the datapad part (not shown) are formed at the edge portion of the thin filmtransistor array substrate 1 which is not overlapped with the colorfilter substrate 2.

Accordingly, the color filter substrates 2 formed on the second mothersubstrate 30 are formed to be separated as long as a first dummy region31 corresponding to the protruded portion of the thin film transistorarray substrates 1 formed on the first mother substrate 20.

The unit liquid crystal panels are suitably disposed such that the firstand the second mother substrates 20 and 30 can be utilized to theirmaximum, and though they differ depending on a model, the unit liquidcrystal panels are usually formed to be separated along a second dummyregion 32.

After the first mother substrate 20 with the thin film transistor arraysubstrates 1 formed thereon and the second mother substrate 30 with thecolor filter substrates 2 formed thereon are attached, the liquidcrystal panels are cut. At this time, the first dummy region 31 formedat the portion where the color filter substrates 2 of the second mothersubstrate 30 are separated and the second dummy region 32 separating theunit liquid crystal panels are simultaneously removed.

The cutting process of the liquid crystal display panel will bedescribed as follows.

FIG. 3 is an exemplary view showing a cutting process of the liquidcrystal display panel.

As shown, a cutting device of the liquid crystal display panel includesa table 42 on which the first and second mother substrates 20 and 30 forwhich previous processes have been terminated, are loaded, and a cuttingwheel 55 for processing the first and second mother substrates 20 and 30to form prearranged cut lines 51.

In the cutting device of the liquid crystal display panel, when thefirst and second mother substrates 20 and 30 including a plurality ofliquid crystal display panels and attached in a facing manner are loadedon the table 42, the cutting wheel 55 positioned at an upper side of thefirst and second mother substrates 20 and 30 is lowered and rotated in astate that certain pressure has been applied to the second mothersubstrate 30, to thereby form prearranged cut lines 51 in a groove formon the surface of the second mother substrate 30.

The prearranged cut lines are also formed on the first mother substrate20. Namely, the first mother substrate 20 is processed with the cuttingwheel 55 to form prearranged cut lines at the same positions as theprearranged cut lines 51 of the second mother substrate 30. Accordingly,in the liquid crystal panel cutting process, since the first and secondmother substrates 20 and 30 are processed to form the prearranged cutlines 51, after the second mother substrate 30 is processed with thecutting wheel 55, the liquid crystal panel is reversed to make the firstmother substrate 20 to face upward and then the first mother substrate20 is processed with the cutting wheel 55.

Thereafter, pressure is applied to the prearranged cut lines 51 formedon the first and second mother substrates 20 and 30 to separate thefirst and second mother substrates 20 and 30. And then, the first andsecond mother substrates 20 and 30 are separated such that the first andsecond mother substrates 20 and 30 are broken with a breaking bar sothat cracking can be made along the prearranged cut lines 51.

In cutting the liquid crystal display panel, a scribing process and abreaking process are performed several times through a plurality ofpasses.

Thus, much time is required for the scribing process and the breakingprocess causing the problem of a reduction in productivity.

In particular, according to the cutting method of the liquid crystaldisplay panel, since the mother substrates are struck with the breakingbar to make cracks along the prearranged cut lines formed on the mothersubstrates, a plurality of glass chips are generated, and if thestriking is not performed inaccurately or if cracking is notincompletely made, the liquid crystal display panel would be damaged ortorn off when it is extracted.

BRIEF DESCRIPTION OF THE INVENTION

Therefore, one aspect of the present invention involves the recognitionby the present inventors of the drawbacks in the related art asexplained above. In order to address such problems, the presentinvention provides a method for cutting a liquid crystal display panelcapable of shortening time required for cutting a liquid crystal displaypanel, and a method for fabricating a liquid crystal display panel usingthe same.

Another aspect of the present invention provides a method for cutting aliquid crystal display panel capable of preventing dropping of a dummyglass when unit liquid crystal display panels are extracted from alarge-scale mother substrate on which prearranged cut lines have beenformed, and a method for fabricating a liquid crystal display panelusing the same.

One feature of the present invention is to provide an apparatus fortransferring a liquid crystal display panel including: a body foradsorbing a liquid crystal display panel and transferring it; and aplate attached on an edge of the body, fixing and separating a dummyglass of a mother substrate from the liquid crystal display panel, andmoving up and down separately from the body.

Another feature of the present invention is to provide a method forcutting a liquid crystal display panel including: forming prearrangedcut lines on a pair of attached mother substrates on which a pluralityof panel regions have been disposed; and separating the liquid crystaldisplay panel from a dummy glass around the liquid crystal display panelthrough a transfer unit which includes a body for adsorbing a liquidcrystal display panel and transferring it, and a plate attached on anedge of the body, fixing and separating a dummy glass of a mothersubstrate from the liquid crystal display panel, and moving up and downseparately from the body.

Still another feature of the present invention is to provide a methodfor fabricating a liquid crystal display panel including: providingmother substrates divided into a plurality of panel regions; performingan array process on the mother substrate for an array substrate andperforming a color filter process on the mother substrate for a colorfilter substrate; forming an alignment film on the surface of the mothersubstrates; performing rubbing on the alignment film-formed mothersubstrates; attaching the pair of rubbing-finished mother substrates;attaching the pair of rubbing-finished mother substrates; formingprearranged cut lines on the pair of attached mother substrates; andseparating the liquid crystal display panel from a dummy glass aroundthe liquid crystal display panel through a transfer unit which includesa body for adsorbing a liquid crystal display panel and transferring it,and a plate attached on an edge of the body, fixing and separating adummy glass of a mother substrate from the liquid crystal display panel,and moving up and down separately from the body.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is an exemplary view showing a plane structure of a unit liquidcrystal display panel formed by attaching a thin film transistor (TFT)array substrate and a color filter substrate in a facing manner;

FIG. 2 is a view showing the structure of a section of the unit liquidcrystal display panel formed by attaching the first mother substrate onwhich the TFT array substrates are formed and the second mothersubstrate on which the color filter substrates are formed;

FIG. 3 is an exemplary view showing a cutting process of a liquidcrystal display panel;

FIG. 4 is an exemplary view showing a cutting process of a liquidcrystal display panel in accordance with the present invention;

FIG. 5 is an exemplary view showing a plane structure of a trans handfor taking out a liquid crystal display panel in accordance with thepresent invention;

FIGS. 6A to 6C are exemplary view showing a process of sequentiallytaking a liquid crystal display panel from a mother substrate andcarrying it using the trans hand;

FIG. 7 is a flow chart illustrating the sequential processes of onemethod for fabricating a liquid crystal display panel in accordance withthe present invention;

FIG. 8 is a flow chart illustrating the sequential processes of anothermethod for fabricating a liquid crystal display panel in accordance withthe present invention; and

FIG. 9 is a flow chart illustrating the sequential processes of a methodfor cutting a liquid crystal display panel in accordance with thepresent invention in FIGS. 7 and 8.

DETAILED DESCRIPTION OF THE INVENTION

A method for cutting a liquid crystal display panel and a method forfabricating a liquid crystal display panel using the same according tothe present invention will be described with reference to theaccompanying drawings.

FIG. 4 is an exemplary view showing a cutting process of a liquidcrystal display panel in accordance with a first embodiment of thepresent invention.

As shown in FIG. 4, a pair of attached mother substrates 101 on which aplurality of panel regions 111 have been arranged are transferred to ascribing part through a conveying unit so as to be divided intoindividual unit liquid crystal display panels along the panel regions111.

The panel regions 111 can be an array substrate on which thin filmtransistors (TFTs) have been formed through an array process, and thelower panel region 111 can be a color filter substrate on which colorfilters have been formed through a color filter process. In thisembodiment of the present invention, the panel regions have the samesize, but the present invention is not limited thereto and the panelregions 111 can be formed with at least two different sizes. In thiscase, the upper array substrate and the lower color filter substrate areattached to form a unit liquid crystal display panel 110.

In the drawing, the conveying unit includes a plurality of conveyerbelts 170, but the present invention is not limited thereto and theconveying unit may include a plurality of transfer rollers. In addition,the conveying unit may include a first convey part formed as a conveyerbelt and a second convey part formed as a transfer roller, which arecoupled.

After the mother substrates 101 are transferred to the scribing part,first prearranged cut lines 151 are formed to section the panel regions111 on the front and rear surfaces of the mother substrates 101 in afirst direction with a scribing unit 180.

The scribing unit 180 driven in an X axis direction includes a pair ofheads (not shown) and repeatedly performs a first scribing process byfour times to form the first prearranged cut lines 151 in the firstdirection, namely, in the X axis direction on the mother substrates 101through the heads.

After the first scribing process in the first direction is finished, ina state that the scribing unit 180 is maintained at a certain positionwith respect to an X axis, the heads of the scribing unit 180 are drivenin a Y axis direction to form second prearranged cut lines 152 forsectioning the panel regions 111 on the front and rear surfaces of themother substrates 101 in a second direction. In this case, in order toform the second prearranged cut lines 152 on the mother substrates 101through the heads, eight times of scribing process are repeated in thesecond direction, namely, in the Y axis direction.

In this case, in this embodiment of the present invention, the firstscribing process is performed four times in the X axis direction and thesecond scribing process is performed eight times in the Y axis directionto form the total eight sheets of liquid crystal display panels 110 onthe large-scale mother substrates 101, but the present invention is notlimited thereto and can be applicable regardless of the number of timesof performing the scribing process in the X and Y axes directions.

The scribing unit 180 includes a head at the upper and lower portionsthereof to form the first and second prearranged cut lines 151 and 152on the front and rear surfaces of the mother substrates 101. A scribingwheel (not shown) made of a material having a higher hardness than glassis mounted at each head.

After the scribing process in the first and second directions isfinished, the mother substrate 101 is moved to the breaking part. In thebreaking part, steam is sprayed onto the front and rear surfaces of themother substrates 101 through a steam break 190 disposed to besubstantially perpendicular to the proceeding direction of the mothersubstrates 101 to make cracks along the prearranged cut lines 151 and152 to thereby separate liquid crystal display panels 110.

Although not shown, the steam break 190 includes a body for receivingwater through a water supply pipe, a heating unit provided inside thebody and heating water supplied through the water supply pipe togenerate steam and a spraying unit for spraying steam generated by theheating unit onto the surface of the mother substrates 101.

Steam generated from the spraying unit is sprayed onto the front andrear surfaces of the mother substrates 101 at a temperature of about100° C.-250° C. to expand the mother substrates 101 made of the glassmaterial according to heat and pressure. In this case, the first andsecond prearranged cut lines 151 and 152 of the mother substrates 101are expanded to be cut therealong, while the mother substrates 101 arebeing transferred to an unloading part.

In this case, an air knife 195 for spraying dried air with a certainpressure is installed at a rear surface of the steam break 190 in orderto remove moisture or glass chips remaining on the surface of the mothersubstrates 101 after the steam is sprayed on the mother substrates 101,and at the same time, proceed with making cracks formed along the firstand second prearranged cut lines 151 and 152.

As stated above, according to the method for cutting the liquid crystaldisplay panel in the first embodiment of the present invention, thefirst prearranged cut lines are simultaneously formed on the front andrear surfaces of the mother substrates and then the scribing heads aredriven in the Y axis direction to simultaneously form the secondprearranged cut lines on the front and rear surfaces of the mothersubstrates. Thus, without having to rotate or reverse the mothersubstrates, the first and second prearranged cut lines can be formed onthe front and rear surfaces of the mother substrates.

In addition, as for the mother substrates 101 on which the first andsecond prearranged cut lines 151 and 152 have been formed, a crack isformed along the first and second prearranged cut lines 151 and 152using the steam break 190 and the air knife 195 to separate the unitliquid crystal display panels 110. Thus, compared with the breakingprocess performed by striking using the break bar, a required time canbe shortened and the liquid crystal display panels 110 can be separatedwithout causing damage thereto.

The unit liquid crystal display panels 110 separated from the mothersubstrates 101 through the scribing process and the breaking process areextracted through a transfer unit such as a trans hand 160 andtransferred to a reversing unit.

In this case, the trans hand 160 also serves to completely separate adummy glass, if any, that has not been separated from the liquid crystaldisplay panels 110 yet through the breaking process.

Namely, a plate 163 with a certain form is attached at an edge of thetrans hand 160 to remove a dummy glass which has not been separated fromthe edge of the liquid crystal display panels 110 before the liquidcrystal display panels 110 are extracted, and then, extracts therespective liquid crystal display panels 110 in an upper direction toseparate them from the mother substrates. By doing that, the problem ofthe related art in which, after the breaking process is performed, theliquid crystal display panels are adsorbed and moved upwardly using thetrans hand and then the dummy glass which has been moved upward togetherwith the liquid crystal display panels are removed using a pusherattached at the edge of the trans hand, and in this case, the dummyglass separated by the pusher may be dropped onto the mother substrateswhich have not been separated yet to damage other liquid crystal displaypanels or the dropped the dummy glass can be caught by the conveyer beltto interfere proceeding of the mother substrates.

FIG. 5 is an exemplary view showing a plane structure of a trans handfor taking out a liquid crystal display panel in accordance with thepresent invention.

As shown in FIG. 5, in the trans hand 160, a plurality of adsorptionmembers 166 are formed on a body 165, through which the liquid crystaldisplay panels are adsorbed to be separate from the mother substrates tobe extracted.

The plate 163 with a certain form is formed at an edge of the body 165of the trans hand 160 in order to remove a dummy glass. In FIG. 5, arectangular plate 163 is shown as an example, but the present inventionis not limited thereto and can be applicable regardless of the form ofthe plate 163.

The plate 163 includes a plurality of cylinders 164 for allowing theplate 163 to be driven separately from the body 165 of the trans hand160, in order to remove the dummy glass which has not been separated yetfrom the liquid crystal display panels before the liquid crystal displaypanels are extracted.

Namely, the plate 163 of the trans hand 160 is driven up and downseparated from the body 165 of the trans hand 160 through the cylinders164 installed at the plate 163 in order to separate and remove the dummyglass around the liquid crystal display panels adsorbed and fixed by theadsorption members 166 from the liquid crystal display panels.

FIGS. 6A to 6C are exemplary view showing a process of sequentiallytaking a liquid crystal display panel from a mother substrate andcarrying it using the trans hand.

First, as shown in FIG. 6A, after the scribing process and the breakingprocess are finished, the mother substrates are transferred to a certainunloading part, and then, the trans hand 160 is moved to an upperportion of the mother substrates so as to be positioned on an upper sideof a certain liquid crystal display panel 110.

Thereafter, the trans hand 160 is moved downward so as to be adsorbedand fixed on the surface of the liquid crystal display panel 110 to beextracted through the adsorption members 166 of the trans hand 160.

In this case, because the rectangular plate 163 is attached at the edgeportion of the trans hand 160, it separates and fixes a dummy glass 112around the liquid crystal display panel 110. As mentioned above, theplate 163 is driven up and down separately from the body 165 of thetrans hand 160 through the cylinders 164 installed at the plate 163, andin this case, the cylinders 164 are driven down so that the plate 163can press and fix the dummy glass 122 around the liquid crystal displaypanel 110 downward.

And then, as shown in FIG. 6B, in a state that the plate 163 and thedummy glass 112 pressed and fixed by the plate 163 are maintained attheir positions, the body 165 of the trans hand 160 is moved up. Then,the liquid crystal display panel 110 adsorbed to the adsorption members166 of the trans hand 160 is completely separated from the dummy glass112 fixed by the plate 163 and moved up.

In this case, the cylinders 164 connected with the plate 163 ismaintained to be driven downward until the dummy glass 112 can becompletely separated from the liquid crystal display panel 110.

After the liquid crystal display panel 110 and the dummy glass 112 arecompletely separated, as shown in FIG. 6C, the cylinders 164 are drivenupward, so that the separated dummy glass 112 is left in the uploadingpart and the liquid crystal display panel 110 adsorbed onto theadsorption members 166 are transferred to the reversing unit.

In this manner, by attaching the rectangular plate 163, instead of apusher, at the edge of the trans hand 160, the dummy glass 112 can beseparated from the liquid crystal display panel 110 in a state that thedummy glass 112 is maintained at is position in the unloading part.Accordingly, when the liquid crystal display panel 110 is extracted, adamage of the liquid crystal display panel 110 by the dummy glass 112can be prevented.

FIG. 7 is a flow chart illustrating the processes of one method forfabricating a liquid crystal display panel in accordance with thepresent invention, and FIG. 8 is a flow chart illustrating the processesof another method for fabricating a liquid crystal display panel inaccordance with the present invention.

Specifically, FIG. 7 shows a method for fabricating an LCD in which aliquid crystal layer is formed by a liquid crystal injection method, andFIG. 8 shows a method for fabricating an LCD in which a liquid crystallayer is formed by a liquid crystal dropping method.

The process for fabricating the liquid crystal display panel can bedivided into a driving device array process for forming a driving deviceon the lower array substrates, a color filter process for forming acolor filter on the upper color filter substrate, and a cell process forattaching the array substrate and the color filter substrate.

To begin with, a plurality of gate lines and a plurality of data linesarranged to define pixel regions on the lower substrate are formed and aTFT switching device is formed to be connected with the gate lines andthe data lines at each of the pixel regions through the array process(step S101). In addition, a pixel electrode which is connected with theTFT and drives the liquid crystal layer as a signal is applied theretothrough the TFT is formed through the array process.

A color filter layer comprising red, green and blue sub-color filtersimplementing color and a common electrode are formed on the uppersubstrate through the color filter process (step S103).

In this respect, when fabricating an in-plane switching (IPS) mode LCDdevice, the common electrodes are formed on the lower substrate on whichthe pixel electrodes have been formed through the array process.

Subsequently, after an alignment film is printed on the upper and lowersubstrates, it is aligned to provide an anchoring force or a surfacefixing force (namely, a pretilt angle and an alignment direction) toliquid crystal molecules of a liquid crystal layer formed between theupper and lower substrates (step S102 and S104).

After the rubbing process is finished, the upper and lower substratesare inspected as to whether its alignment films are defective or notthrough an alignment film inspecting device (step S105).

The liquid crystal display panel uses electro-optic effects of liquidcrystal, and since the electric optical effect is determined byanisotropy of the liquid crystal itself and a state of arrangement ofliquid crystal molecules, controlling of the arrangement of liquidcrystal molecules has much influence on stabilization of a displayquality of the liquid crystal display panel.

Accordingly, the alignment film forming process for effectively aligningliquid crystal molecules is of much importance with respect tocharacteristics of picture quality in the liquid crystal cell process.

A method for inspecting the rubbing deficiency includes a firstinspection process which determines whether the coated alignment filmhas a blur, a strip or a pin hole on its surface or not, and a secondinspection process in which uniformity of the surface of the rubbedalignment film is checked and whether the surface of the rubbedalignment film has a scratch or not.

After the inspecting of the alignment film is finished, as shown in FIG.7, spacers for uniformly maintaining a cell gap are formed on the lowersubstrate and a sealant is coated on an outer edge of the uppersubstrate. And then, the lower and upper substrates are attached byapplying a pressure thereto (steps S106-S108). In this case, the spacerscan be ball spacers according to a spreading method, or can be columnarspacers formed through patterning.

The lower and upper substrates are formed as large-scale glasssubstrates. In other words, a plurality of panel regions are formed onthe large-scale glass substrates, and the TFT, the driving device, andthe color filter layer are formed at each panel region. Thus, in orderto obtain a unit liquid crystal display panel, the glass substrates areto be cut and processed (step S109).

In this case, in order to separate the mother substrates into individualliquid crystal panels, the method for cutting a liquid crystal displaypanel in accordance with the present invention is used, which will nowbe described in detail with reference to FIG. 9.

FIG. 9 is a flow chart illustrating the sequential processes of a methodfor cutting a liquid crystal display panel in accordance with thepresent invention in FIGS. 7 and 8.

First, the pair of attached mother substrates on which the plurality ofpanel regions have been formed are loaded and transferred to the firstscribing unit through the transfer unit (step S201). In this case, theTFTs, driving elements, and the color filter substrates have been formedon the upper and lower panels.

After being transferred to the scribing unit, the first prearranged cutlines are formed to section the panel regions on the front and rearsurfaces of the mother substrates through the first scribing unit.

After the first scribing process in the first direction is finished, thehead provided at the scribing unit is driven in a Y axis direction toform second prearranged cut lines for sectioning the panel regions onthe front and rear surfaces of the mother substrates.

In this manner, according to the method for cutting liquid crystaldisplay panels, after the first prearranged cut lines are simultaneouslyformed on the front and rear surfaces of the mother substrates, thescribing head is driven in the Y axis direction to simultaneously formthe second prearranged cut lines on the front and rear surfaces of themother substrates. Thus, without having to rotate and reverse the mothersubstrates several times, the first and second prearranged cut lines canbe formed on the front and rear surfaces of the mother substrates (stepS202).

After the scribing process in the first and second directions isfinished, the mother substrates are moved to the breaking part, andsteam and dried air are sprayed onto the front and rear surfaces of themother substrates through a steam break and an air knife. Then, a crackis formed along the prearranged cut lines and each panel region and thedummy glass of the mother substrates are separated and then transferredto the unloading part (step S203).

The trans hand if moved to an upper side of the mother substrates andpositioned at an upper side of a certain panel region.

And then, the trans hand is moved down, and a surfaces of a liquidcrystal display panel to be extracted is adsorbed and fixed through theadsorption members (step S204).

In this case, since the rectangular plate is attached at the edge of thetrans hand, it can separate and fixes the dummy glass around the liquidcrystal display panel from the liquid crystal display panel (step S205).

Thereafter, in a state that the plate and the dummy glass pressed andfixed by the plate are maintained at their positions, the body of thetrans hand is moved up. Then, the liquid crystal display panel adsorbedto the adsorption members of the trans hand is completely separated fromthe dummy glass fixed by the plate and moved up (step S206) In thiscase, the cylinders connected with the plate is maintained to be drivendownward until the dummy glass can be completely separated from theliquid crystal display panel.

After the liquid crystal display panel and the dummy glass arecompletely separated, the cylinders 164 are driven upward, so that theseparated dummy glass is left in the uploading part and the liquidcrystal display panel adsorbed onto the adsorption members 166 istransferred to the reversing unit.

Thereafter, as shown in FIG. 7, liquid crystal is injected through aliquid crystal injection opening in each unit liquid crystal displaypanel, the liquid crystal injection opening is sealed to form a liquidcrystal layer, and then each unit liquid crystal display panel isinspected, thereby completing fabrication of each of the unit liquidcrystal display panels (steps S110 and S111).

The liquid crystal is injected using a vacuum injection method using apressure difference. That is, according to the vacuum injection method,the liquid crystal injection opening of the unit liquid crystal displaypanel separated from the large-scale mother substrates is put in acontainer filled with liquid crystal in a chamber with a certain degreeof vacuum, and then, the degree of vacuum is changed to allow liquidcrystal to be injected into the liquid crystal display panel accordingto a pressure difference between the interior and the exterior of theliquid crystal display panel. When the liquid crystal is filled insidethe liquid crystal display panel, the liquid crystal injection openingis sealed to form the liquid crystal layer of the liquid crystal displaypanel. Thus, in order to form the liquid crystal layer at the liquidcrystal display panel through the vacuum injection method, a portion ofa seal pattern needs to be opened to serve as the liquid crystalinjection opening.

However, the vacuum injection method has the following problem.

That is, first, it takes a long time to fill the liquid crystal in theliquid crystal display panel. In general, because the attached liquidcrystal display panel has an area of hundreds of cm² and a gap of merelyabout a few μm, the amount of injected liquid crystal per unit hour isvery small when the vacuum injection method using the pressuredifference is employed. For example, about eight hours are required tofill a 15-inch panel with liquid crystal. Since that much time isrequired for fabrication of the liquid crystal display panel, theproductivity is degraded. In addition, as the liquid crystal displaypanel is increased in size, time taken for filling liquid crystal wouldbe more lengthened and a defective filling of liquid crystal would alsooccur, resulting in that it cannot cope with the enlargement of theliquid crystal display panel.

Second, a large amount of liquid crystal is used. In general, the amountof liquid crystal actually injected into the liquid crystal displaypanel is quite small compared with the amount of liquid crystal filledin the container, and when liquid crystal is exposed in the air orexposed to a specific gas, it is reacted to the gas and degraded. Thus,although the liquid crystal filled in the container is filled in theplurality of unit liquid crystal display panels, a large amount ofliquid crystal remaining after finishing the filling is discarded, andaccordingly, the unit cost of the liquid crystal panel is increased onlyto weaken price competitiveness of the product.

In order to solve the problem of the vacuum injection method, thedropping method is increasingly employed.

As shown in FIG. 8, when using the dropping method, after the alignmentfilm is inspected (step S105), a seal pattern is formed with a sealanton the color filter substrate and, at the same time, a liquid crystallayer is formed on the array substrate (steps S106′ and S107′).

According to the dropping method, after liquid crystal is dropped anddispensed on the large-scale first mother substrate where a plurality ofarray substrates are disposed or on an image display region of thesecond mother substrate where the plurality of color filter substratesare disposed, the first and second mother substrates are attached byapplying a certain pressure thereto to thereby make the liquid crystaluniformly distributed to the entire image display region and thus form aliquid crystal layer.

Thus, in the case where the liquid crystal layer is formed in the liquidcrystal display panel through the dropping method, the seal pattern mustbe formed as a closed pattern surrounding the outer edge of the pixelpart region in order to prevent a leakage of liquid crystal to outsideof the image display region.

The dropping method allows dropping of liquid crystal within arelatively short time compared with the vacuum injection method and canquickly form the liquid crystal even when the liquid crystal displaypanel is large.

In addition, since only the required amount of liquid crystal is droppedon the substrate, an increase in the unit cost of the liquid crystaldisplay panel due to the discarding of the high-priced liquid crystal asin the vacuum injection method can be prevented, and thus, the pricecompetitiveness of the product can be enhanced.

Thereafter, when the upper and lower substrates on which liquid crystalhas been dropped and the sealant has been coated are aligned, a pressureis applied thereto to make the lower and upper substrate attached by thesealant and simultaneously the dropped liquid crystal spread uniformlyon the entire portion of the panel (step S108′).

Through the process, the plurality of liquid crystal display panels withthe liquid crystal layer formed thereon are formed on the large-scaleglass substrates (upper and lower substrates). The glass substrates areprocessed and cut to be separated into the plurality of liquid crystaldisplay panels, which are then inspected to thereby finish fabricationof the liquid crystal display panel (steps S109′ and S110′).

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A method for cutting a liquid crystal display panel comprising:forming cut lines on a pair of attached mother substrates on which aplurality of panel regions have been disposed; and separating the liquidcrystal display panel from a dummy glass around the liquid crystaldisplay panel through a transfer unit, said transfer unit including abody for adsorbing a liquid crystal display panel and transferring itand a plate attached on an edge of the body; fixing and separating adummy glass of a mother substrate from the liquid crystal display panel;and moving up and down separately from the body of the transfer unit. 2.The method of claim 1, wherein the step of forming the cut lines on thepair of mother substrates comprises: transferring to a scribing part thepair of attached mother substrates on which the panel regions have beendisposed; and forming first and second cut lines on the front and rearsurfaces of the mother substrates with a scribing unit.
 3. The method ofclaim 2, further comprising: transferring the mother substrates on whichthe first and second cut lines have been formed to a breaking part andseparating them into a plurality of unit liquid crystal display panels.4. The method of claim 3, wherein the mother substrates are conveyed tothe scribing part and the breaking part through a conveying unit.
 5. Themethod of claim 4, wherein the conveying unit comprises a plurality ofconveyer belts.
 6. The method of claim 4, wherein the conveying unitcomprises a plurality of transfer rollers.
 7. The method of claim 4,wherein the transfer unit comprises a first convey part formed as aconveyer belt and a second convey part formed as a transfer roller,which are coupled.
 8. The method of claim 3, wherein the mothersubstrates are separated along the first and second cut lines byspraying steam through steam breaks disposed at front and rear surfacesof the mother substrates.
 9. The method of claim 8, wherein moisture andglass chips remaining on the surfaces of the mother substrates areremoved by spraying dried air through an air knife installed at rearsurfaces of the steam breaks.
 10. The method of claim 2, wherein thestep of forming the first and second cut lines on the front and rearsurfaces of the mother substrates comprises: forming the first cut linesfor sectioning the panel regions on the front and rear substrates of themother substrates in a first direction with a scribing unit; and formingthe second cut lines for sectioning the panel regions on the front andrear substrates of the mother substrates in a second direction bydriving a head provided at the scribing unit in a second direction. 11.The method of claim 2, wherein the first and second cut lines aresubstantially cross vertically.
 12. The method of claim 1, wherein thestep of separating the liquid crystal display panels from a dummy glassaround the liquid crystal display panels comprises: moving a transferunit having a plate is attached at an edge of a body to an upper side ofa certain liquid crystal display panel; moving the transfer unitdownward to adsorb a surface of the liquid crystal display panel to beextracted through adsorption members installed on the body; and drivingthe body upward in a state that the dummy glass around the liquidcrystal display panel through the plate, to separate the liquid crystaldisplay panel from the dummy glass.
 13. The method of claim 1, furthercomprising: a plurality of cylinders connected with the plate and drivenup and down separately from the body.
 14. The method of claim 13,wherein the cylinders are driven down to press and fix the dummy glassaround the liquid crystal display panel downward through the plate. 15.The method of claim 13, wherein when the body is moved up, the plate andthe cylinders are maintained to be driven downward until the dummy glassis completely separated from the liquid crystal display panel.
 16. Themethod of claim 1, wherein the body includes a plurality of adsorptionmembers, adsorbs the surface of the liquid crystal display panel throughthe adsorption members, and transfers it to the following process. 17.The method of claim 1, wherein the plate has a frame form.
 18. Themethod of claim 17, wherein the frame has a form corresponding to thatof the liquid crystal display panels.